The invention relates to an imaging device comprising a light source, an image carrier and an effervescence generator comprising a liquid-containing unit and propagation means for gas and for liquid contained in the liquid-containing unit wherein the effervescence generator and the light source are arranged at a first side of the image carrier, and wherein means are provided for controlled light projection through at least a part of the effervescence generator and through the image carrier in order to obtain a combined image at the second side situated opposite the first side of the image carrier.
Such an imaging device is known from the international patent application PCT/NL94/00328. This known imaging device has a liquid-containing unit comprising a submersible pump which, together with a pipe running through the liquid-containing unit, forms a closed circuit. Water is pumped through the pipe while at the same time the submersible pump draws in air which can escape in the form of bubbles through holes provided in the wall of the pipe. In this way bubbles rise in the effervescence generator and their image in combination with the image fixed on the image carrier is visible outside the imaging device.
Basically, these known imaging devices comply with various desirable optical effects. For instance a moving picture, such as a waterfall, can be produced or, more usual, the imaging device can be placed indoors or outdoors for advertising purposes, in particular for bubbling or carbonated drinks. For an expert it will be obvious that such drinks may be both alcoholic and non-alcoholic.
However, the known imaging device is not always suitable for procuring the desired illusion for someone observing the image created by means of the imaging device, viz. said device requires further improvement. A first problem with the known imaging device is that the bubbles in the liquid-containing unit follow a fairly uncontrolled path and that the size of the bubbles is such that a true-to-nature reproduction of the bubbling drink or beer or champagne is not very easily produced.
Another problem of the known imaging device is that the reproduction of a dynamic flow, other than upward, cannot be realized.
A third problem is that the rotating or swirling bubbling up of the bubbles in the known device does not correspond with the fairly linear movement of bubbles in a standing glass of carbonated drink.
A fourth problem is that the dynamic flow effects which occur, for instance when pouring a glass of soft drink or beer, cannot be imitated in the known imaging device.
The invention intends to solve these and other problems and to provide further advantages which will be elucidated below.